High-performance MIM capacitors using HfLaO-based dielectrics

Abstract

Metalinsulatormetal (MIM) capacitors fabricated with (8%) La-doped HfO 2 single layer as well as HfLaO/LaAlO3HfLaO multilayer dielectric stack are demonstrated. While the La-doped HfO2 single layer is crystallized at 420 C° annealing, HfLaO/LaAlO3/HfLaO multilayer dielectric stack remains amorphous. A high dielectric-constant value of 38 can be obtained when 8% La-doped HfO2 is crystallized into cubiclike structure. However, it is observed that the linearity of MIM capacitor is degraded upon crystallization. The multilayer film has lower average dielectric constant but shows low quadratic voltage linearity of less than 1000 ppm/V2 up to a capacitance density of 9 fF/μm2. It is observed that the HfLaO single-layer MIM is suitable for the applications with requirements of high capacitance density and robust reliability, while the multilayer MIM is suitable for a precision circuit. © 2006 IEEE.